1. Field
Apparatuses and methods consistent with exemplary embodiment relate to adjusting hue in an image processing device.
2. Description of the Related Art
In image processing devices such as a monitoring camera, auto white balance (AWB) processing is performed to deal with a color temperature of a broad light source. AWB is a function of analyzing components of three primary colors of red, green, and blue (RGB) in an entire screen and properly calculating an R-component amplification degree and a B-component amplification degree according to an acquired screen. However, for example, when a Natrium lamp having an extremely low color temperature is used as a light source to capture an image, it may be impossible to approach original color reproduction only by adjusting an R-component amplification degree and a B-component amplification degree. Thus, in this case, a process of approaching original color reproduction may be performed by compulsively changing hue using a hue adjustment function.
The hue adjustment function is realized by converting primary components of RGB to brightness and hue components of YCbCr and rotating the brightness and hue components of YCbCr about a two-dimensional (2D) coordinate space of Cb and Cr. In this case, if the brightness and hue components of YCbCr are rotated about all coordinate spaces, hue of the entire screen is changed. Thus, for the 2D coordinate space of Cb and Cr, a plurality of regions are previously defined using angle areas based on a central point.
According to a related art, an entire image is divided into eight regions, regions of pixels to be processed are determined, every region is previously rotated by a predefined angle, and a rotating result is output. When this method is applied, if gradation exists over a plurality of adjacent regions, or if there is a big difference between angles designated to the plurality of adjacent regions, a large gradation gap due to rotation angle processing occurs at the boundary of the angle of the regions.
To prevent this, when there is a rotation angle difference between adjacent regions, rotation angles are commonly interpolated so that there is no problem in the hue of gradation. However, when rotation angles are interpolated in a fixed boundary of adjacent regions, although a large hue difference is removed, a value different from an originally designated rotation angle may be applied due to the interpolation.